Rock crusher



P 7, 19.65 P. R. VIFIAN ETAL 3,204,882

ROCK CRUSHER Filed June 15, 1962 3 Sheets-Sheet l P 1965 P. R. VIFIAN ETAL 3,204,882

ROCK GRUSHER Filed June 15, 1962 3 Sheets-Sheet 2 P 1965 P. R. VIFIAN ETAL 3,204,882

ROCK CRUSHER Filed June 15, 1962 3 Sheets-Sheet 3 United States Patent 3,204,882 RUCK CRUSIFER Paul R. Vitian and Albert B. Hanse, Cedar Rapids, Iowa,

assignors to Pettibone Mulliken Corporation, a corporation of Deiaware Filed June 15, 1962, Ser. No. 202,733 17 Claims. (Cl. 241 275) The present invention relates to an apparatus for crushing rock or the like, of the type wherein the rock is deposited upon a rotating table from which it is thrown against an anvil which surrounds the table.

In rock ciushers of the type with which the present invention deals, the wear of the parts contacted by the rock is a significent problem. The time and labor involved in shutting down the operation and replacing the parts is costly. When the parts must be replaced at very frequent intervals, the number of replacement parts and the cost thereof can be an important factor. While special materials can be employed to reduce the wear, and the parts formed so that they are readily replaceable, such steps do not eliminate the problem. If special materials are employed to increase their service life, the cost per unit is increased because of the increased cost of the special materials and, in some instances, the fabrication cost of forming the parts from the special materials.

The extent to which the parts Will Wear in a given period of operation will vary substantially with the type of material that is being crushed. The composition of many rocks is much more abrasive than others. Variations therein will have a signficant effect on the wear of parts. While the term rock has been used herein, crushers of this type are used with many materials having much the same properties but which are not a natural stone. For example, a crusher of this type often is employed in the crushing of slag. The term rock as used herein is not intended to exclude such other materials as might be processed in a crusher of this type, but is employed to merely indicate the general category of material-s with which a crusher of this type might be employed.

Judging from the rock crushers of this type as generally used in the industry, it has been the theory that it was necessary for satisfactory crushing not only to impact the rock against the anvils surrounding the rotary table, but also to impact the rock against members projecting upwardly from the top surface of the table. Because of the wear problems these projecting members are protected with replaceable shoes. However, an important factor in the wear of the shoes is the impacting of these shoes on the stone. have discovered that successful crushing can be achieved merely by impacting the rock against the anvil. By our unique construction, we substantially eliminate any impact between the rock and the shoes on the table. This factor alone greatly increases the service life of the shoes. In our invention the structure projecting upwardly from the top of the table is so positioned that there is a steady, even, and smooth flow of the rock from the central portion of the table outwardly about the shoes to the edge of the table from which point it is thrown against the anvil.

A second factor that causes shoe wear is the friction of the stone sliding along the shoe face. In this position the stone is acted upon by a force which urges the stone against the shoe face. The extent to which the stone tends to gouge (or wear) the face of the shoe will be directly In contradistinction to this prior art, we'

'ice

affected by (1) the magnitude of the force between the stone and the shoe face, and (2) the angle between the line of force acting upon the stone and the face of the shoe. The smaller that the magnitude of the force is, the less will be the tendency of the stone to gouge the shoe. Also, the smaller that the angle between the line of the force and the face of the shoe is, the less will be the tendency of the stone to gouge the shoe.

While we avoid using the shoes on the table as impact members, we retain them to enable machines of our invention to impart a high velocity to the stone as it leaves the table to impact against the anvil surrounding the table. By reason of a novel positioning of the shoes we are able to reduce the frictional wear of the stones moving along the shoes toward the periphery of the table.

The structure of our invention is such that at the points at which the force of the stone against the face of the shoe is the greatest, i.e. where the centrifugal forces are greatest, the force is applied to the shoe at a small acute angle. This limits the tendency of the stone to gouge the shoe in those areas. To the extent that it is necessary to create a flow pattern such that, at some point, the gouging angle of the stone on the shoe will be more nearly normal to the face of the shoe, our structure creates a flow pattern in which this undesirable result only will occur adjacent the center of the table. Adjacent the center of the table the forces acting on the stone are the smallest. Since at these points the forces are low, the resultant wear is not serious despite the fact that the gouging angle is larger.

A further factor which contributes to an effective crushing machine with reduced wear is the incorporation of means for substantially reducing the impact of the shoes with rock that splatters from the anvil faces back onto the rotating table. We have discovered that the rock that splatters back onto the table will impact with the rotating shoe faces in such a manner as to be a substan tial factor in the wear of the shoe faces. By greatly re ducing or substantially eliminating the splatter of rock back onto the table the service life of the shoes is improved.

We achieve eifective distintegration of the rock by impacting it solely against the faces of the anvil surrounding the rotating table. We have discovered a particular positioning of the anvil faces which are extremely effective in achieving disintegration.

Another feature of our invention that contributes to the production of a desirable and effective rock crusher with reduced wear, is the incorporation of an air recirculation duct between the intake and discharge sides of the crusher. A rock crusher without this feature is undesirable to those who must work with it since great amounts of dust are blown out about the crusher. Not only does this dust create undesirable working conditions, but it gets into adjacent machinery, e.g. the motor driving the crusher, and results in substantial wear because of its abrasiveness. The air re-circulation duct of. our invention substantially keeps the dust confined within the crusher and eliminates the problems resulting from the blowing of the dust into the atmosphere about the crusher.

Further objects and advantages of our invention will become apparent from the following description taken in conjunction With the drawings in which:

FIGURE 1 is a side elevation of a rock crusher embodying our invention;

FIGURE 2 is an end elevation of the crusher;

per).

of FIGURE 6;

FIGURE 8 is a partial section corresponding to FIG- URE 4 and illustrating still further alternative features of our invention; and

FIGURE 9 is a partial section as viewed at line 9-9 of FIGURE 8.

Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

General description Referring to FIGURES 1 and 2, the illustrated embodiment includes a frame generally 10. On the frame is mounted a casing 11 of the crusher. The crusher is powered by an electric motor 12. The crushed rock is taken from the crusher by a belt conveyor generally 13. Conveyor 13 includes a belt 14 and is of a conven tional structure. The details of a suitable conveyor will be apparent to those skilled in the art.

Within casing 11 is a rotating table 15, mounted on the top of a shaft journaled .in post 16 for rotation about a vertical axis (designated 54 in FIGURE A multiple sheave 17 is secured to the bottom end of the shaft. A multiple sheave 18 is attached to the shaft of motor 12. A plurality of belts 19 interconnect sheaves 17 and =18 to drive table from motor 12.

On table 15 are .a plurality of shoes generally 20. As

hereinafter described, shoes 20 deflect the rock from table 15 against a surrounding anvil 21 to fracture the rock.

The rock is delivered to the crusher through a chute 23, which terminates in a tube 24. The tube 24 is concentric with the axis of rotation of table 15, and is of a size to deposit the rock in a given .area on the center of the tolp of the table.

At the bottom of the crusher, casing 11 tapers inwardly to define a discharge hopper 25. Hopper 25 is closed at all sides and is open at the bottom with the bottom being immediately above the upper face of belt 14 of conveyor 13 (which actually closes the bottom of the hop- Thus the crushed rock will be deposited upon the tolp of belt 14 to be carried .away in the direction in -dicated by arrow 26. At the side of hopper 25 through which the rock must move as it is carried away by belt 14, is a door 27. Door 27 is pivotally mounted on a pin 28 and is urged downwardly toward the top of belt 14 by gravity. As rock moves up belt 14 in the direction indicated by arrow 26, the rock will push the door open to allow the rock to move out of hopper 25. At other times door 27 will remain closed.

A duct 30 has its lower end in communication with hopper 25 and its upper end in communication with feed chute 23. In normal operation feed chute 23 will be kept full of rock to be crushed to a level substantially 'table to impact against the shoe faces.

above the top end of air duct 36). If desired, a screen 31 may be employed at the top end of the air duct to prevent the rock from chute 23 from entering the air duct.

A crusher of the type described has an air action cor responding to that of a centrifugal fan. Tube 24 serves as an air intake and the bottom of thecrusher as an air outlet. Since substantial amounts of dust are created in the crusher these normally are blown out the air outlet and discharged into atmosphere. In our invention the dust will "be trapped in discharge hop per 25. The air in hopper 25, with its entrained dust, will be drawn through duct 30 back to intake chute 23 due to the substantial negative air pressure at intake chute 23. Thus the dust is trapped in the machine and is not blown out into the surrounding atmosphere.

Referring to FIGURES 3 and 4, there are a plurality of lugs 33 secured to the Walls of casing 11. Anvil 21 is made in a plurality of sections. In the back of each section are a plurality of openings 34 corresponding in position to the position of lugs 33. Each of openings 34 defines a downwardly projecting flange 35 in the anvil 21. Flange 35 hooks over the top o f the respective lug 33 to hold the anvil in place.

Anvil 21 define's a plurality of striking faces 36. Referring to FIGURE. 4, table .15 is rotated in the direction indicated by arrow 37. As table 15 rotates, the various striking faces 36 of anvil 21 will successively be facing one of the working faces 38 of shoes 20. The specific positioning of striking faces 36 of anvil 21 is important. This positioning will hereinafter be discussed in detail in connection with the FIGURE 5.

Referring to FIGURE 4 it will be seen that, as viewed from above, the shape of table 15 is approximately oval. As hereinafter described, a table shaping of this type is one of the means by which a reduction is achieved in amount of splattered rock that is redeposited upon the Shoes 26 are positioned adjacent the periphery of table 15 in the two lobes defined by the approximately oval configuration of the table.

Secured to the upper face of the table are a pair of L shaped mounting brackets 40. Angle braces 41 are secured both to brackets 40 and to table 15. Shoes 20 have rectangular tongues 42 which project through a correspondingly shaped opening in one leg of brackets 40. A Wedge 43 is driven into an opening 44 in tongue 42 as best seen in FtIGURE 4. Opening 44 tapers from each side to the center at substantially the same angle as that of wedge 43. Thus shoe 24) may be removed (by driving out the wedge), reversed end for end, and reinserted with the wedge in the opposite side of opening 44. The wedge always should enter the inner end of the opening 44 to prevent its being dislodged by shock and centrifugal force.

Bafiles 46 have stud bolts 47 secured thereto. Bolts 47 project through elongated openings 48 with nuts 49 being secured on the opposite sides of brackets 40. Openings 48 are elongated in the direction of the length of the leg of brackets 40 to permit an adjustment of the position of baffles 46 thereon. Bafiies 46 can be reversed end for end and/ or adjusted laterally of the leg bracket 40 to which the shoes are fixed to compensate for wear on the baffles. ecured to table 15 and independent of bafiies 46 are deflector wings 50.

As best seen in FIGURE 4, baffles 46 are positioned immediately outside the central area of table 15, upon which central area the rock will be deposited from tube 24. In the normal operation of the crusher the rock will flow outwardly to the two lobes of table 15 within the path defined by dotted lines 52 in FIGURE 4. It

will be noted that the path of flow, as related to the direction of rotation indicated by arrow 37, actually appears to be forwardly to reach the inner corner 56 of the shoe 20. This path of flow is caused by the confinement of the rock by the bafiles 46 at the central portion of the rotating table. By forcing the rock to flow in the pattern illustrated, the rock moves onto and across the front face 38 of the shoe substantially'tangent thereto rather than impacting against face 38 as in .prior art devices. In normal operation this flow will take place in the illustrated pattern even without the presence of wings 50. Thus, in the usual case, wings 50 may be dispensed with. When they are employed they are positioned outside the normal flow path, as indicated by lines 52. Confinement of the rock results in a chocking of the flow. A free flow is important.

However, in those instances in which the table occasionally is rotated at a speed slower than normal, the wings 50 are important in order to preserve the desired flow path. At slow speed operation, without wings 50, some of the rock will escape from table 15 before it fiows out to the table periphery immediately adjacent the ends of shoes 20. For example, the rock would flow out in the areas which are closed by the existence of Wings 50 in FIGURE 4. In so doing, it has a lower velocity against the anvil faces and is less likely to be fractured.

The axis of inlet tube 24 and the rotational axis of the table 54 are coincident. We prefer to position the inner corner of the front face of the shoe a distance from the rotational axis such that it is greater than the distance from the axis of the tube to the sides thereof.

In normal operation we prefer to rotate table 15 in the direction indicated by arrow 37 at a speed of between approximately 600 to 2100 rpm. However, the speed of rotation will be varied depending upon various factors, e.g. the characteristics of the material being crushed, the size of the material and the desired crushed size, the size of the table, etc. With some types of rock lower speeds are perfectly satisfactory. With other types of rock, it is desirable to use the higher speeds within this range to achieve a greater impact force. One skilled in the art will have no difiiculty in adjusting the speed to obtain desired results under a given set of conditions. Since the dynamic problems associated with rotating members which are likely not to be fully balanced, as is the case with respect to the table 15 with its varying load of rocks, it is desirable not to use a speed of rotation greatly in excess of that necessary to do a satisfactory job.

FIGURE 5 illustrates the principles (as we best understand them) which result in decreased wear of the shoes in the structure we have devised. One important factor is that the forward faces 38 of the shoes 20 are laid back from a radial line from the axis of rotation of of table 15. By laid back we mean that the outer end 55 of the shoe is rearwardly (with respect to the direction of rotation) of a radial line through an inwardly portion of the shoe. In FIGURE 5 the axis of rotation of table 15 is represented by dot 54.

The face 38 of shoe 20 is curvilinear. In the illustrated embodiment, for reasons that will hereinafter be apparent, this curve of the face is a segment of a circle. With a shoe of this type, the angle at which the shoe is laid back is measured between chord 58 and radius 59 extending through inner end 56 of shoe 20. Similarly with shoes having curved, but non-circular shoe faces the positioned angle is determined with reference to a straight line from end to end of the shoe and the term chord is used herein to refer to such a line both for circular and non-circular shoe faces. Of course, if the shoe face is straight, that is the line used to determine the angle. This chord, or straight face as the case may be, is referred to herein as the line of alignment of the shoe face.

The angle a between chord 58 (line of alignment) and radius 59 is about 52 /2 degrees in the illustrated embodiment. The objects of our invention could be achieved with angle a varying between about 10 degrees and about 90 degrees. The angle a would apply whether the shoe 20 had a straight face (in that case the face being represented by line 58) or had a curvature other than that illustrated by face 38. Such embodiment would achieve 6 some of the improvements of our invention over the prior art. However, as indicated hereinafter, the use of a curved face similar to that illustrated at 3-8 provides additional advantages. Also, as the maximum of about 90 degrees is approached, a curved face shoe becomes almost a requisite.

FIGURE 5 also illustrates two force diagrams to indicate the relative effect of a stone on face 38 of the shoe 20 at different points along that face. Referring first to the smaller of the two force diagrams (the one closer to axis 54), a stone at point 61 on face 38 of the shoe will be acted upon by two forces. Force fl is a radial force representing the centrifugal force tending to move the stone outwardly from axis 5 of the table. Force 12 is at right angles to force f1 and is the force which resists the rotation of the table and shoe. In the absence of friction, force f1 would be equal to force f2. However, because friction will be present, force 1 will be less than force f2 and has been so drawn in the diagram.

Force f3 is the resultant of the two forces f1 and f2. It represents the force actually being applied by the stone to the face of the shoe at point 61. Line 62 is a tangential line to face 38 at point 61. Angle b is the angle between tangential line 62 and the resultant force f3.

Now referring to the larger of the two force diagrams in FIGURE 5, the corresponding set of forces will represent the action of a stone at point 63 on face 38. Force f4 is the radial force tending to move the stone outwardly. Force f5 is at right angles to force f4 and larger because of the effect of friction as hereinbefore described. Force f6 is the resultant of the two forces f4 and f5. Line 64 is a line tangent to face 38 at point 63. Angle c is the angle between tangential line 64 and resultant force f6. Angle 0, like angle b, represents the direction of the gouging force of a stone at a point on the face 38 of shoe 20.

It should be mentioned that the two force diagrams in FIGURE 5 are for purposes of illustration only. No conclusion should be drawn from the specific differences in sizes of the forces. For example, force fl is illustrated with a line which is of the length of force f2. While this represents the effect of friction on a stone at point 61, it is not intended to thereby state that this is the exact difference caused by friction. Similarly, force f4 is 80% of force f5. Also, force id is half-again as large as force f2. This is to illustrate the fact that at a greater distance from axis 54 the forces will be greater. It is not intended to infer that this is the exact increase in force at a greater distance from axis 54.

It will be noted that the gouging angle b in the small force diagram is greater than the gouging angle 0 in the large force diagram. Considering this factor alone, a stone at point 61 would cause greater wear on shoe 20 than would a stone at point 63. However, the forces acting upon a stone at point 61 are smaller than the forces acting upon a stone at point 63. Considering this latter factor alone, the wear at point 61 would be less than the wear at point 63. The foregoing two factors are offsetting. Thus, by reason of the curved configuration of face 38 of shoe 20, the wear on the face is more evenly distributed than would be the case if the shoe had a flat face (as represented by line 58). By reducing the gouging angle (0 being smaller than b), as the gouging forces increase (f6 being larger than f3) the harmful action of a stone on the shoe is ameliorated.

While the shoes in the disclosed embodiments are formed as a single unit it will be apparent to those skilled in the art that they could be formed of a plurality of units and still embody our invention described herein. Such modifications are within the spirit of our invention.

FIGURE 5 also illustrates the proper positioning of the striking faces 36 of anvil 21. Line 66 is a line normal to the face 36 at the center thereof. It intersects the periphery of table 15 at a point 67. Line 68 is a radial line through point 67.

-anvil faces rebounds onto the top of the table.

Point 67 represents the point of departure of a stone from the edge of table 15. Merely to facilitate illustration in FIGURE 5, it is drawn somewhat ahead of shoe 2%. Actually of course, most of the stones will depart from table 15 at a point along the edge of the table substantially closer to shoe 20. However, for the considerations here involved the effect will be the same, whether the stone departs from the table immediately adjacent end 55 of the shoe or somewhat forwardly thereof.

The angle d is the angle between the line 66, normal to the center of face 36, and the radius 68 drawn to the point of intersection of line 66 and the periphery of the table. We prefer to construct anvil 21 so that faces 66 are positioned with angle d being 51 degrees. The results of our invention can be achieved with angle d being as small as about 45 degrees and as large as about 60 degrees.

In the prior art it has been deemed to be desirable to use a circular table as illustrated in FIGURE 4 in dotted lines. It will be seen that in the table 15 we employ, considerable portions have been cut away from a circular shape to define the approximately oval shape of our table. We have discovered that this substantially reduces the extent to which splattering rock from the By substantially diminishing the amount of rebounding rock on the table, we achieved decreased shoe wear. When the splattering rock rebounds onto the conventional round table, it drifts back along the table until it strikes the next shoe face 38. Impact directly on the shoe face 38 has been determined to be a substantial factor in the wear and the needed replacement of shoes 20. Because table 15 is turning rapidly,

a stone thrown from the table at one shoe face and striking an anvil face 36 will (to the extent that it rebounds towards the table) tend to drop from the table shortly behind the shoe from which it was thrown. Since on our table this area is cut away, as indicated by the difference between the dotted line and the solid table edge, the rebounding stone will fall below the table and pass from the crusher.

Means other than the approximately oval table may be employed to reduce the impact of rebounding stone against the shoe faces. Portions of the table 15 rearwardly of the shoes might be cut away to reduce the amount of rebounding stone that will impact against the subsequent shoe face without resulting in a table that looks oval in shape.

FIGURES 6 and 7 illustrate another alternative embodiment. In this embodiment table 15 is round as in the conventional structures. A swinging hammer 70 is pivotally mounted on pin 71 to the rear of each shoe 20 as related to direction of rotation 37. Pin 71 is parallel to the axis of rotation of table 15'. It is supported in a bracket 72 secured to the top of table 15. Bracket 72 includes an angle brace 73. Hammer '76 overhangs the periphery of table 15'. Normally the hammer is held in the position illustrated in FIGURES 6 and 7 by the centrifugal force resulting from the rotation of table 15'.

In the operation of the embodiment of FIGURES 6 and 7 the rock will be deposited upon table 1.5 and flow out about the faces 38 of shoes 20 as hereinbefore described. The rock will be thrown from table 15 immediately in front of each of the shoes 20 and will be impacted against faces 36 of anvil 21. The impact will shatter the rock. Some of the shattered rock will rebound directly towards table 15 in a position and with sufiicient force that normally it would be deposited upon the surface of table 15 to the rear of the shoe 24 from which it left the table. The position of hammer 70 is such that it will intercept the majority of the splattering rock so directed, and will prevent it from reaching the table.

Hammer 70 is positioned substantially closer to anvil 21 than is the periphery of table 15. Thus, it will act to strike a lot of the rebounding rock, including some rock that would otherwise drop between the periphery of the table and the anvil. Additional impacts on the rock thus will be achieved with the result that a greater amount of smaller sized rocks will be produced in the output of the crusher. If by these impacts a stone is not crushed sufficiently to move out of the way of hammer '70 and down between the hammer and anvil, hammer will swing rearwardly (with respect to direction 37) allowing the stone then to drop between the anvil and the table. When such a large stone has passed, hammer 70 will return to the illustrated position by the centrifugal force applied thereto.

We are aware that in some prior art crushers, hammers have been used as the primary striking means. In such devices the hammers take a lot of wear with a substantial replacement cost. In our invention they are used only as a secondary impacting means. Since only a portion of the crushed rock is impacted against the hammers, their service life is substantially increased. If hammers 70 are to be used solely to prevent splatter of rock back onto table 15 they need not be positioned with as much overhang beyond the edge of the table as that illustrated in FIGURES 6 and 7. With the outer end of the hammer closer to the outer edge of the table less rock will rebound from the anvil against the hammer. In that case hammer life will be additionally increased.

FIGURES 8 and 9 illustrate two further alternative embodiments to control the rock splattering problems that have affected the wear of prior art crusher structures. Either of these two alternatives illustrated in FIGURES 8 and 9 could be employed apart from the other.

As best seen in FIGURE 8, bracket 40 has a rearwardly extending portion 75. Bracket 40 otherwise corresponds to bracket 40 previously described. Secured to this rearwardly extending portion is a secondary shoe 76. Shoe 76 has a tongue 77 which fits through a correspondingly shaped opening in rearward portion of bracket 48'. In an opening 78 in tongue 77 is driven a wedge 79 to affix shoe 76 in place.

Shoe 76 extends inwardly from the edge of round table 15. It, of course, is positioned rearwardly of shoe 20 as considered with respect to the direction of rotation 37. Being so positioned, shoe 76 will intercept splattering rock from the anvil, which rock otherwise would drop on table 15' and drift back around the table to impact against the next shoe face 38.

The second alternative illustrated in FIGURES 8 and 9 for ameliorating the problem of rebounding rock is the shape of the impact faces of anvil 82. As best seen in FIGURE 9, anvil 82 has a plurality of pairs of impact faces 83 and 84, rather than the single impact faces 36 of the other embodiments. Faces 83 and 84 are approximately at right angles to each other. Each of impact faces 83 and 84- are approximately at a 45 degree angle to the plane defined by the upper surface of table 15. The line of juncture 85 between faces 83 and 84 is approximately level with the upper surface of table 15. When viewed in plan as in FIGURE 8, faces 83 and 84 are at an angle with respect to the edge of table 15 corresponding to that illustrated in FIGURE 5. To put it another way, a line normal to line 85 at its middle, when extended to the periphery of table 15, will intersect a radial line at the same point at an angle between about 45 degrees and about 60 degrees.

In an anvil structure illustrated in FIGURES 8 and 9, the stone thrown from table 15' initially will impact against face 83 of the anvil. From face 83 the stone normally will rebound downwardly and in the majority of instances impact against the lower face 84 of the anvil. From face 84 the stone will drop under table 15'. Such an anvil construction will substantially prevent any upward splattering of the rock and the deposit of rock from the anvil back onto table 15.

We claim:

1. In a rock crusher having a table rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, and a replaceable shoe above the table, releasably aflixed thereto and adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, the improvement comprising: said face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; and a baflle commencing at the inner end of the shoe and extending rearwardly therefrom to initially confine the rock to the central portion of the table and cause it to flow outwardly about the inner end of the shoe.

2. The improvement in a rock crusher as set forth in claim 1, wherein said face is convex.

3. The improvement in a rock crusher as set forth in claim 1, wherein the line of alignment of the face is positioned between about and about 90 from a radial line to the inner end of the shoe.

4. In a rock crusher as set forth in claim 1 and including an anvil member surrounding the table, the improvement wherein the table includes means to reduce the extent to which rock will splatter from the anvil member back onto the table and drift back along the table to impact against the shoe.

5. The improvement in a rock crusher as set forth in claim 4, wherein said means is a deflector positioned forwardly, with respect to the direction of rotation, of the shoe, and a baffle between the central portion of the table and the deflector.

6. The improvement in a rock crusher as set forth in claim 5, wherein the deflector comprises a hammer pivotable with respect to the table about a second axis parallel to the first axis.

7. In a rock crusher having a table rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, replaceable shoes releasably afiixed adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, and an anvil member surrounding the table and against which the rock is thrown, the improvement comprising: said table being generally normal to said axis and having an approximately oval upper face with two lobes; one of said shoes positioned on each lobe, said face of each shoe being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; and a baffle commencing at the inner end of each shoe and extending rearwardly therefrom to initially confine the rock to the central portion of the table and cause it to flow outwardly about the inner ends of the shoes.

8. A rock crusher including: a casing; a table mounted in said casing for rotation about a generally vertical axis; means connected to the table to rotate the table in a given direction; a chute to direct the rock onto a central portion of the table; a pair of replaceable shoes releasably afiixed to the table, said shoes being positioned adjacent the periphery of the table and approximately 180 apart, each shoe having a forwardly, with respect to said direction of rotation, face, each face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; a bafiie positioned outside the central portion and extending rearwardly, with respect to the direction of rotation, from the inner end of the shoe; and an anvil surrounding the table, said anvil having a plurality of striking faces jutting inwardly and facing the shoe faces as the table rotates, said striking faces being positioned such that a first line normal to a second line defined by the intersection of a horizontal plane with the striking face and at the center of the second line will, when extended to a point at the edge of the table at the outer end of a shoe, intersect a radial line through said point at an angle of from about 45 to about 60.

9. A rock crusher including: a casing; a table mounted in said casing for rotation about a generally vertical axis; means connected to the table to rotate the table in a given direction; a chute to direct the rock onto a central portion of the table; a pair of replaceable shoes releasably affixed to the table, said shoes being positioned adjacent the periphery of the table and approximately apart, each shoe having a forwardly, with respect to said direction of rotation, face, each face being positioned angu larly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; a bathe positioned outside the central portion and extending rearwardly, with respect to the direction of rotation, from the inner end of the shoe; and an anvil surrounding the table, said anvil having a plurality of striking faces jutting inwardly and facing the shoe faces as the table rotates, said striking faces being positioned such that a first line normal to a second line defined by the intersection of a horizontal plane with the striking face and at the center of the second line will, when extended to a point at the edge of the table at the outer end of a shoe, intersect a radial line through said point at an angle approximately 51.

10. A rock crusher including: a casing having a rock intake opening at the top thereof and a rock discharge opening at the bottom thereof; a table mounted in said casing for rotation about a generally vertical axis; means connected to the table to rotate the table in a given direction; a chute to direct the rock onto a central portion of the table; a pair of replaceable shoes releasably affixed to the table, said shoes being positioned adjacent the periphery of the table and approximately 180 apart, each shoe having a forwardly, with respect to said direction of rotation, face, each face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; a bafifie positioned outside the central portion and extending rearwardly, with respect to the direction of rotation, from the inner end of the shoe; an anvil surrounding the table, said anvil having a plurality of striking faces jutting inwardly and facing the shoe faces as the table rotates, said striking faces being positioned such that a first line normal to a second line defined by the intersection of a horizontal plane with the striking face and at the center of the second line will, when extended to a point at the edge of the table at the other end of a shoe, intersect a radial line through said point at an angle of from about 45 to about 60; and an air duct communicating with the interior of said casing above and below said table and independently of the interior of the casing.

11. In a rock crusher comprising a casing having a rock intake opening at the top thereof and a rock discharge opening at the bottom thereof, a table in said casing and rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, a replaceable shoe releasably afiixed adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, and an anvil member surrounding the table and against which the rock is thrown, the improvement comprising: an air duct communciating with the interior of said casing above and below said table and independently of the interior of the casing; means associated with said opening to permit crushed rock to be removed from said machine while preventing substantial ingress of air through said opening; said face being positioned angularly with respect to the radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; and a battle commencing at the inner end of the shoe and extending rearwardly therefrom to initially confine the rock to the central portion of the table and cause it to flow outwardly about the inner end of the shoe.

12. In a rock crusher comprising a casing having a rock intake opening at the top thereof and a rock discharge opening at the bottom thereof, a table in said casing and rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, a replaceable shoe releasably affixed adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, and an anvil member surrounding the table and against which the rock is thrown, the improvement comprising: an air duct communicating with the interior of said casing above and below said table and independently of the interior of the casing; a normally closed door closing the discharge opening; said face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; and a baffle commencing at the inner end of the shoe and extending rearwardly therefrom to initially confine the rock to the central portion of the table and cause it to flow outwardly about the inner end of the shoe.

13. A rock crusher including: a casing; a table mounted on said casing for rotation about a generally vertical axis; means connected to the table to rotate the table in a given direction; a chute to direct the rock onto a central portion of the table; a pair of replaceable shoes releasably afiixed to the table, said shoes being positioned adjacent the periphery of the table and approximately 180 apart, each shoe having a forwardly, with respect to said direction of rotation, face, each face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; a bafiie positioned outside the central portion and extending rearwardly, with respect to the direction of rotation, from the inner end of the shoe; and an anvil surrounding the table, said anvil having a plurality of pairs of striking faces comprising an upper and a lower face, said pairs jutting inwardly and facing the shoe faces as the table rotates, the upper face of a pair facing downwardly at about a 45 angle and the lower face of a pair facing upwardly at about a 45 angle, the upper and lower faces intersecting approximately level with the top of the table, said striking faces being positioned such that a first line normal to a second line defined by the intersection of a horizontal plane with a striking face and at the center of the second line will, when extended to a point at the edge of the table at the outer end of a shoe, intersect a radial line through said point at an angle of from about 45 to 60.

14. In a rock crusher having a table rotating about a vertical axis with the rock being deposited on a cen-- the table and against which the rock is thrown, the im provement comprising: said anvil having a plurality of pairs of striking faces comprising an upper and a lower i2 face, said pairs jutting inwardly and facing the shoe faces as the table rotates, the upper face of a pair facing downwardly at about a angle and the lower face of a pair facing upwardly at about a 45 angle, the upper and lower faces intersecting approximately level with the top of the table, said striking faces being positioned such that a line normal to a second line defined by the intersection of a horizontal plane with the striking face and at the center of the second line will, when extended to a point at the edge of the table at the outer end of a shoe, intersect a radial line through said point at an angle of from about 45 to about 15. In a rock crusher having a table rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, a replaceable shoe releasably affixed adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, and an anvil member surrounding the table and against which the rock is thrown, the improvement comprising: said anvil having a plurality of pairs of striking faces comprising an upper and a lower face, said pairs jutting inwardly and facing the shoe faces as the table rotates, the upper face of a pair facing downwardly at about a 45 angle and the lower face of a pair facing upwardly at about a 45 angle, the upper and lower faces intersecting approximately level with the top of the table.

16. In a rock crusher having a table rotating about a vertical axis with the rock being deposited on a central portion thereof and thrown off by the rotation in a given direction, replaceable shoes releasably afiixed adjacent the periphery of the table with a forward, with respect to the direction of rotation, face to propel the rock from the table, and an anvil member surrounding the table and against which the rock is thrown, the improvement comprising: said table being oval in shape with two lobes; one of said shoes positioned on each lobe adjacent the edge of the table, said face being positioned angularly with respect to a radial line from said axis through the shoe, the angular position being such that the inner end of the shoe is forwardly and the outer end is rearwardly with respect to said direction of rotation; baflies extending across each side of said central area of the table in a direction rearwardly from said inner ends of the shoes; and curved deflectors extending from approximately the portion of the baffies closest to the axis of rotation rearwardly about the central area to a point spaced forwardly of the inner end of the other of the shoes.

17. A rock crusher including: a casing; a table mounted on said casing for rotation about a generally vertical axis; means connected to the table to rotate the table in a given direction; a chute to direct the rock onto a central portion of the table; a pair of replaceable shoes releasably aflixed to the table, said shoes being positioned adjacent the periphery of the table and approximately 180 apart, each shoe having a forwardly, with respect to said direction of rotation, face, the line of alignment of each face being at an angle of from about 10 to about from a radial line at the inner end of the shoe with said shoe extending rearwardly, with respect to said direction of rotation, of said radial line, said shoes having convex forwardly faces, a baflie positioned outside the central portion and extending rearwardly, with respect to the direction of rotation, from the inner end of the shoe; and an anvil surrounding the table, said anvil having a plurality of pairs of striking faces comprising an upper and a lower face, said pairs jutting inwardly and facing the shoe faces as the table rotates, the upper face of a pair facing downwardly at about a 45 angle and the lower face of a pair facing upwardly at about a 45 angle, the upper and lower faces intersecting approximately level with the top of the table, said striking faces being positioned such that a first line normal to a second line defined by the intersection of a horizontal 1 3 plane with a striking face and at the center of the second line will, when extended to a point at the edge of the table at the outer end of a shoe, intersect a radial line through said point at an angle of from about 45 to 60.

References Cited by the Examiner UNITED STATES PATENTS 11/26 Bell 2415 14 Werner et a1 241-275 X Jones 24148 Coss et a1. 241275 Horth 241275 Adams 241275 Sellars 241-275 Bridgewater 241275 X J. SPENCER OVERHOLSER, Primary Examiner. 

1. IN A ROCK CRUSHER HAVING A TABLE ROTATING ABOUT A VERTICAL AXIS WITH THE ROCK BEING DEPOSITED ON A CENTRAL PORTION THEREOF AND THROWN OFF BY THE ROTATION IN A GIVEN DIRECTION, AND A REPLACEABLE SHOE ABOVE THE TABLE, RELEASABLY AFFIXED THERETO AND ADJACENT THE PERIPHERY OF THE TABLE WITH A FORWARD, WITH RESPECT TO THE DIRECTION OF ROTATION, FACE TO PROPEL THE ROCK FROM THE TABLE, THE IMPROVEMENT COMPRISING: SAID FACE BEING POSITIONED ANGULARLY WITH RESPECT TO A RADIAL LINE FROM SAID AXIS THROUGH THE SHOE, THE ANGULAR POSITION BEING SUCH THAT THE INNER END OF THE SHOE IS FORWARDLY AND THE OUTER END IS REARWARDLY WITH RESPECT TO SAID DIRECTION OF ROTATION; AND A BAFFLE COMMENCING AT THE INNER END OF THE SHOE AND EXTENDING REARWARDLY THEREFROM TO INITIALLY CONFINE THE ROCK TO THE CENTRAL PORTION OF THE TABLE AND CAUSE IT TO FLOW OUTWARDLY ABOUT THE INNER END OF THE SHOE. 